The present invention generally relates to a container for a viscous medium and, more specifically, to such a container from which a controllable amount of the liquid may be selectively dispensed. The container of the invention is particularly well suited for use with appropriately viscous cosmetic compositions, such as toothpaste.
German DOS No. 3,611,644 discloses a container for viscous cosmetics--such as toothpaste--from which the same may be manually dispensed. The container is provided with an inwardly displaceable piston forming its bottom and secured by a pawl against relatively outward movement, and a compressable container portion formed of a flexible, elastic material such as a polyester elastomer and including a dispensing mouthpiece. A dispensing valve arranged within the container before the inlet cross-section of the mouthpiece is opened on an increase in interior container pressure and is formed of a plastic material shaped in a pot-like configuration. A circular flap comprising the pot bottom is normally urged against a projection to close the dispensing mouthpiece inlet. However, a suitable increase in the internal pressure of the container effected by compression of the flexible container portion causes the flap--which has a maximum diameter of approximately 10 mm--to move from its seat into the valve cross-section so as to open the mouthpiece inlet and enable an outward, dispensing flow of the contained viscous composition under the force of increased internal pressure.
The above-described container suffers from a variety of drawbacks. The required internal pressure increase, which is operatively effected by the exertion of pressure on the container mouthpiece, must be relatively great. Yet due to the elasticity of the flexible container portion and the operative configuration of the valving assembly, accurate control of the proportion of the contained liquid contents dispensed is difficult if at all possible. Moreover, unless the container is completely filled with the composition to be dispensed, the presence of air pockets or inclusions can seriously hamper reliable functioning of the dispensing container. Still further, manufacture and assembly of the various parts comprising the container--and particularly those forming the valving apparatus thereof--are relatively costly and complex and relatively stringent production tolerances must be observed.
It is accordingly the object of the invention to provide a container for dispensing a viscous liquid composition that overcomes the disadvantages and problems of the prior art. More particularly, it is an object to provide such a container that is readily operable to dispense a relatively controllable quantity of the contained liquid, that is reliable in continued use, and that may be readily manufactured and assembled of a minimum number of component parts at relatively low cost.
The present invention consists at least in part of the features of construction, combinations of elements, and arrangements of components which is exemplified in the construction hereinafter described and of which the scope is indicated by the appended claims.